present invention generally relates to golf club heads and particularly relates a golf club head aiming at prevention of its sole plate from peeling off from its head body and an improvement of its impact property.
Recently, there has been proposed a golf club called a "wood" having a head body which is made by compression-forming a layer of fiber-reinforced resin, such as carbon-fiber-reinforced resin, glass-fiber-reinforced resin, or the like, on a surface of a core material made of foam synthetic resin or the like, as a substitute for making the head body out of natural wood such as wood of a kaki tree or Japanese persimmon tree, wood of a cherry tree, or the like, in the viewpoints of stability of quality, easiness in supply of
materials, and so on. At a sole portion of such a head body, a sole plate made of aluminum, brass or the like is attached.
Conventionally, such a sole plate is inserted together with a material for forming a head body into a cavity of a mold and integrally thermally pressed so that the sole plate is attached to the head body. Further, recently, as disclosed, for example, in Japanese Patent application (OPI) No. Sho-62-170271 (the term "OPI" as used herein means an "unexamined published application") . A protrusion (or a sole plate support pin) having a substantially T-shaped section is provided on a sole plate so that the protrusion projects into a head body to aim at prevention of the sole plate from peeling off by means of the protrusion. Further, Japanese Patent Application (OPI) No. Sho-63-71272 discloses a golf club head of carbon iron having a structure in which a protrusion is provided on a sole plate so as to project up from the sole plate into a head body.
In such a conventional structure as disclosed in the Japanese Patent Application (OPI) No. Sho-62-170271, however, there has been a problem that the weight of the protrusion is added to the inside of the golf club head so as to reduce the moment of inertia to thereby lower the impact property because the protrusion is T-shaped in section so that the ends of the protrusion project not only to the outside of the head body but to the inside of the same, while the sole plate can be surely prevented from peeling off because of the T-shaped section of the protrusion. Further, in the latter conventional structure disclosed in the Japanese Patent Application (OPI) No. Sho-63-71272, there has been a problem that the prevention of peeling-off of the sole plate from the head body is not sufficient.